Vehicles, such as aircraft, spacecraft, and automobiles often have critical hydraulic, pneumatic, fuel, thermal, electrical, or mechanical systems positioned within close proximity of on-board turbines or high-speed engine components. In the event of structural failure of a turbine or engine, it is possible that the high-speed components of the turbine or engine may become high-energy projectiles, and that such projectiles may damage critical systems of the vehicle.
By way of example, automobiles often contain brake lines, fuel lines, and electrical cables located in close proximity to the main engine of the automobile. Upon structural failure of the engine, it is possible that components of the engine may become high speed projectiles and may damage one or more of the brake, fuel, or electrical lines. Further, it is possible that a high-energy projectile may be introduced into the passenger compartment through the fire wall of the automobile.
By way of another example, spacecraft such as the Space Shuttle contain several turbine driven components and, although the likelihood of turbine failure is minimal, consequences of a structural turbine failure aboard a spacecraft are particularly serious. For instance, the Space Shuttle contains Auxiliary Power Units (APUs), Solid Rocket Booster Hydraulic Power Units (HPUs), and Space Shuttle Main Engine (SSME) Turbo Pumps, each of which comprise high speed turbines in close proximity to safety critical pneumatic, thermal, fuel, or hydraulic components.
The APUs aboard the Shuttle are of particular interest when examining the possible consequences of turbine failure. Each APU is a hydrazine-fueled, turbine-driven power unit that generates mechanical shaft power to drive a hydraulic pump that produces pressure for the orbiter's hydraulic system. Aboard the Shuttle, there are three separate APUs, three hydraulic pumps and three hydraulic systems.
The turbines of the APUs are designed for operation between 74,160 rpm to 82,800 rpm. In the event of an APU overspeed event or other structural failure of the turbine, it is possible that the APU hydrazine tanks could be damaged by fragments of the turbine. Fragments of the turbine could also damage hydraulic lines that are critical for control or operation of the Shuttle.
Critical systems of spacecraft, and vehicles in general, are conventionally protected with thermal and acoustic insulation. The thermal insulation provides protection from environmental temperature variations, while the acoustic insulation provides protection from external vibrations. But, conventional thermal and acoustic insulation systems do not provide protection from high-energy projectiles, such as those produced upon failure of high-speed engines or turbines.
It is desired to provide critical fluid systems of aircraft, spacecraft, and automobiles, as well as other vehicles, machinery, and equipment having high speed turbines or engines with a protective system capable of protecting the critical systems from impact by high-energy projectiles. It is further desired to provide protection from projectiles while providing any thermal or acoustic protection desired for operation of the critical systems.